New Delhi:- The countdown for the new year 2017 will be delayed by a second as horologists will compensate for a slowdown in the Earth’s rotation.
The National Physical Laboratory (NPL) is to introduce a “leap second” after 23.59:59 on December 31.
“The Earth and rotation around its own axis is not regular, as sometimes it speeds up and sometimes it slows down, due to various factors including the moon’s gravitational Earth-braking forces that often results in ocean tides.
“As a result, Astronomical Time (UT1) gradually falls out of sync with Atomic time (UTC), and as and when the difference between UTC and UT1 approaches 0.9 seconds, a leap second is added to UTC through Atomic clocks worldwide,” D K Aswal, Director National Physical Laboratory said .
India too will add a “leap second” in its “atomic clock” in order to synchronise clocks worldwide with the Earth and ever slowing rotation.
Atomic clocks are very accurate and are stable within one second over a period of millions of years. On the other hand, the Astronomical Time known as Universal Time (UT1) refers to the Earth and rotation around its own axis and determines the length of a day.
As the leap second is added simultaneously all over the world at UTC 23:59:59 on December 31, 2016, a leap second will also be inserted at IST 05:29:59 on January 1, 2017 (IST being five hours and thirty minutes ahead of UTC (Coordinated Universal Time).
Adding the leap second to Indian clock is done by National Physical Laboratory (NPL) under the Council for Scientific and Industrial Research (SCIR). The NPL is one of the oldest laboratory in the country.
In order to follow Indian Standard Time (IST), the clocks need to be adjusted after the insertion of leap second.
Those utilising CSIR-NPL time dissemination services need not worry as they will receive the corrected time post the insertion of leap second, Aswal said.
“The leap second adjustment is not so relevant for normal everyday life. However this shift is critical for applications requiring of time accuracies in the nanosecond, which are critical in the fields of astronomy, satellite navigation, communication networks,” Aswal added.
Since 1972, 36 leap seconds have been added at intervals varying from six months to seven years and this will be 37th year.
PTI
